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Eurosceptics believe ending EU payments after Brexit is more important than stopping free movement, a new poll has found in a warning shot to Theresa May.

The Prime Minister has repeatedly declined to rule out paying the EU to securing some of the bloc’s advantages, saying only any amount will not be “vast”.

The findings put pressure on Mrs May as she attempts to deliver on the Brexit vote while minimising economic disruption in two years of negotiations.

The polling of 10,000 voters - one of the biggest surveys of public opinion since the EU referendum - was conducted by former Tory donor Lord Ashcroft.

There was support for the Prime Minister’s stance on not protecting EU citizens’ rights until a reciprocal deal has been agreed for Britons on the Continent.

It was also found that more Britons want immigration control prioritised during Brexit talks than single market access.

One voter said in a focus group: “If [the Prime Minister] has to choose, it’s got to be the people side of it. Tariff-free trade benefits the EU more than us because of our trade deficit.

“She’s got to be able to say we’re only allowing certain people in at certain times – that’s what people voted for. Trade is a bit of a red herring.”

The cost of Britain’s EU membership was a central part of the referendum campaign, with a controversial Leave claim that the bill was £350 million a week emblazoned on their bus.

Since the Brexit vote Mrs May - who backed staying in the EU - has sought to prove her determination to deliver on the result.

She has said Britain will not be staying in the single market or the customs union in its current form, to the delight of her Eurosceptic backbench.

However she has left open the possibility of continued EU payments and backed a transition period for embedding Brexit - something hardliners would not have adopted.

New polling shows the political risk of such a move. People were asked to rate the importance of four possible negotiation targets out of 100.

Leave voters rated ending payments to the EU budget as 85 out of 100 in importance and stopping the rule of the European Courts of Justice as 80 out of 100.

Both issues were judged to be more important than picking which EU citizens can live in Britain - often seen as the driver behind the Leave vote - and tarrif-free access.

Lord Ashcroft, writing an analysis of the poll in this paper, suggests that the findings could create an issue for the Prime Minister in the coming years.

“Voters feel, quite understandably, that we will not really have left the EU – and that their decision has not been honoured – if we still pay into it, are subject to its laws and allow unfettered immigration for its citizens,” he writes.

“But those who also believe all of this can be achieved without affecting our trading arrangements or anything else will have to be disabused of the notion sooner rather than later.”

In a boost to the Prime Minister, voters supported her EU citizens stance. Fifty five per cent said it was correct not to guarantee their rights until Britons in the EU get the same confirmation.

The poll, which was carried out in late March, also reveals the full scale of Labour’s collapse in support under Jeremy Corbyn.

Mrs May enjoys a 37-point lead in who would make the best prime minister over Mr Corbyn, with 55 per cent of voters saying her and just 18 per cent supporting him. Even among Labour voters, Mrs May is favoured to their own leader.